Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d891992766f0fde…

MALICIOUS

PDF

93.8 KB Created: 2021-09-08 06:38:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1f3bba51644bbb9b541da8bdbc8adea7 SHA-1: cf2098572a5e0f2b1dd2db3c51cc0f17fb8b5c88 SHA-256: 8d891992766f0fde6134098c5a5fa71c02d2ec2ae02516136eb74e4743e4685f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external URIs and links to compromised CMS uploads, indicating it's part of a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload. The file's structure and numerous links point towards a tactic of distributing further malicious content through a network of compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://cructi.ru/uplcv?utm_term=delineamento+em+quadrado+latino+pdf
    • http://synhbio.com/upload/files/70530319106.pdf
    • http://kindergartenhelden.at/upload/file/nadikopalu.pdf
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/pepav.pdf
    • http://hp-cnc.de/uploads/files/torutubajawa.pdf
    • https://taiyotech.jp/userfiles/file/dovetof.pdf
    • http://mudrkanuch.sk/editor_uploads/system/files/19885336497.pdf
    • https://pellevah.com/upload/files/wenajur.pdf
    • http://flexa.cz/docs/file/78547231821.pdf
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/gmq5hqklkgr3llojigk5cb6mcm/24263892536.pdf
    • http://gostinica-domodedovo.ru/files/bofexa.pdf
    • https://777mto.org/contents/files/muselul.pdf
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/08ecee98ba9a66fea6c7f8498e1127f8/kupevew.pdf
    • https://doanhnghiepvietnam.org/img_duhoc/files/38136802159.pdf
    • http://npi-management.org/ressource/site-image/files/lowegunifizifim.pdf
    • http://andreaslasnik.com/data/files/vizomerogejifif.pdf
    • http://ssaisarang.com/ckfinder/userfiles/files/mozaveve.pdf
    • http://a-kamen.com/userfiles/file/99572206245.pdf
    • http://avsa.org/sites/default/files/images/files/wigozitebikazomum.pdf
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/xigubevij.pdf
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/53387f583b47c258a39c6d274c8c0f65/masovadolutozi.pdf
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d26764caf1f---pabipaxovobobev.pdf
    • http://nwhouse.ru/uploads/file/nizafifonugu.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e443923e2f8---pufurekod.pdf
    • https://angelsstaff.com/uploads/file/vopelof.pdf
    • http://brnc85.com/clients/878796/File/45056405627.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000100ca.bin
7a29871a76805923f7f5b9ed58f74655229725b9e6eb74043a646f09846ebbdf
pdf-font-stream PDF embedded font (sfnt) at offset 0x100CA 10736 bytes
font_01_sfnt_off00011924.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11924 16792 bytes
font_02_sfnt_off00013136.bin
8cd9edbeca0753dad7878161a82ae3840c9bc367f31c3cf2662308efe555b15d
pdf-font-stream PDF embedded font (sfnt) at offset 0x13136 21412 bytes